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Sakagami K, Igawa T, Saikawa K, Sakaguchi Y, Hossain N, Kato C, Kinemori K, Suzuki N, Suzuki M, Kawaguchi A, Ochi H, Tajika Y, Ogino H. Development of a heat-stable alkaline phosphatase reporter system for cis-regulatory analysis and its application to 3D digital imaging of Xenopus embryonic tissues. Dev Growth Differ 2024; 66:256-265. [PMID: 38439617 DOI: 10.1111/dgd.12919] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2023] [Revised: 02/16/2024] [Accepted: 02/19/2024] [Indexed: 03/06/2024]
Abstract
Xenopus is one of the essential model systems for studying vertebrate development. However, one drawback of this system is that, because of the opacity of Xenopus embryos, 3D imaging analysis is limited to surface structures, explant cultures, and post-embryonic tadpoles. To develop a technique for 3D tissue/organ imaging in whole Xenopus embryos, we identified optimal conditions for using placental alkaline phosphatase (PLAP) as a transgenic reporter and applied it to the correlative light microscopy and block-face imaging (CoMBI) method for visualization of PLAP-expressing tissues/organs. In embryos whose endogenous alkaline phosphatase activities were heat-inactivated, PLAP staining visualized various tissue-specific enhancer/promoter activities in a manner consistent with green fluorescent protein (GFP) fluorescence. Furthermore, PLAP staining appeared to be more sensitive than GFP fluorescence as a reporter, and the resulting expression patterns were not mosaic, in striking contrast to the mosaic staining pattern of β-galactosidase expressed from the lacZ gene that was introduced by the same transgenesis method. Owing to efficient penetration of alkaline phosphatase substrates, PLAP activity was detected in deep tissues, such as the developing brain, spinal cord, heart, and somites, by whole-mount staining. The stained embryos were analyzed by the CoMBI method, resulting in the digital reconstruction of 3D images of the PLAP-expressing tissues. These results demonstrate the efficacy of the PLAP reporter system for detecting enhancer/promoter activities driving deep tissue expression and its combination with the CoMBI method as a powerful approach for 3D digital imaging analysis of specific tissue/organ structures in Xenopus embryos.
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Affiliation(s)
- Kiyo Sakagami
- Department of Animal Bioscience, Nagahama Institute of Bio-Science and Technology, Nagahama, Japan
| | - Takeshi Igawa
- Amphibian Research Center, Graduate School of Integrated Sciences for Life, Hiroshima University, Hiroshima, Japan
| | - Kaori Saikawa
- Department of Animal Bioscience, Nagahama Institute of Bio-Science and Technology, Nagahama, Japan
| | - Yusuke Sakaguchi
- Amphibian Research Center, Graduate School of Integrated Sciences for Life, Hiroshima University, Hiroshima, Japan
| | - Nusrat Hossain
- Amphibian Research Center, Graduate School of Integrated Sciences for Life, Hiroshima University, Hiroshima, Japan
- Department of Pharmaceutical Sciences, North South University, Dhaka, Bangladesh
| | - Chiho Kato
- Department of Animal Bioscience, Nagahama Institute of Bio-Science and Technology, Nagahama, Japan
| | - Kazuhito Kinemori
- Amphibian Research Center, Graduate School of Integrated Sciences for Life, Hiroshima University, Hiroshima, Japan
| | - Nanoka Suzuki
- Amphibian Research Center, Graduate School of Integrated Sciences for Life, Hiroshima University, Hiroshima, Japan
| | - Makoto Suzuki
- Amphibian Research Center, Graduate School of Integrated Sciences for Life, Hiroshima University, Hiroshima, Japan
| | - Akane Kawaguchi
- Department of Genomics and Evolutionary Biology, National Institute of Genetics, Shizuoka, Japan
| | - Haruki Ochi
- Institute for Promotion of Medical Science Research, Faculty of Medicine, Yamagata University, Yamagata, Japan
| | - Yuki Tajika
- Department of Radiological Technology, Gunma Prefectural College of Health Sciences, Maebashi, Japan
| | - Hajime Ogino
- Amphibian Research Center, Graduate School of Integrated Sciences for Life, Hiroshima University, Hiroshima, Japan
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Hossain N, Igawa T, Suzuki M, Tazawa I, Nakao Y, Hayashi T, Suzuki N, Ogino H. Phenotype-genotype relationships in Xenopus sox9 crispants provide insights into campomelic dysplasia and vertebrate jaw evolution. Dev Growth Differ 2023; 65:481-497. [PMID: 37505799 DOI: 10.1111/dgd.12884] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2023] [Revised: 07/20/2023] [Accepted: 07/21/2023] [Indexed: 07/29/2023]
Abstract
Since CRISPR-based genome editing technology works effectively in the diploid frog Xenopus tropicalis, a growing number of studies have successfully modeled human genetic diseases in this species. However, most of their targets were limited to non-syndromic diseases that exhibit abnormalities in a small fraction of tissues or organs in the body. This is likely because of the complexity of interpreting the phenotypic variations resulting from somatic mosaic mutations generated in the founder animals (crispants). In this study, we attempted to model the syndromic disease campomelic dysplasia (CD) by generating sox9 crispants in X. tropicalis. The resulting crispants failed to form neural crest cells at neurula stages and exhibited various combinations of jaw, gill, ear, heart, and gut defects at tadpole stages, recapitulating part of the syndromic phenotype of CD patients. Genotyping of the crispants with a variety of allelic series of mutations suggested that the heart and gut defects depend primarily on frame-shift mutations expected to be null, whereas the jaw, gill, and ear defects could be induced not only by such mutations but also by in-frame deletion mutations expected to delete part of the jawed vertebrate-specific domain from the encoded Sox9 protein. These results demonstrate that Xenopus crispants are useful for investigating the phenotype-genotype relationships behind syndromic diseases and examining the tissue-specific role of each functional domain within a single protein, providing novel insights into vertebrate jaw evolution.
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Affiliation(s)
- Nusrat Hossain
- Amphibian Research Center, Hiroshima University, Hiroshima, Japan
- Graduate School of Integrated Sciences for Life, Hiroshima University, Hiroshima, Japan
| | - Takeshi Igawa
- Amphibian Research Center, Hiroshima University, Hiroshima, Japan
- Graduate School of Integrated Sciences for Life, Hiroshima University, Hiroshima, Japan
| | - Makoto Suzuki
- Amphibian Research Center, Hiroshima University, Hiroshima, Japan
- Graduate School of Integrated Sciences for Life, Hiroshima University, Hiroshima, Japan
| | - Ichiro Tazawa
- Amphibian Research Center, Hiroshima University, Hiroshima, Japan
- Graduate School of Integrated Sciences for Life, Hiroshima University, Hiroshima, Japan
| | - Yuta Nakao
- Amphibian Research Center, Hiroshima University, Hiroshima, Japan
- Graduate School of Integrated Sciences for Life, Hiroshima University, Hiroshima, Japan
| | - Toshinori Hayashi
- Amphibian Research Center, Hiroshima University, Hiroshima, Japan
- Graduate School of Integrated Sciences for Life, Hiroshima University, Hiroshima, Japan
| | - Nanoka Suzuki
- Amphibian Research Center, Hiroshima University, Hiroshima, Japan
| | - Hajime Ogino
- Amphibian Research Center, Hiroshima University, Hiroshima, Japan
- Graduate School of Integrated Sciences for Life, Hiroshima University, Hiroshima, Japan
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Aquatic Freshwater Vertebrate Models of Epilepsy Pathology: Past Discoveries and Future Directions for Therapeutic Discovery. Int J Mol Sci 2022; 23:ijms23158608. [PMID: 35955745 PMCID: PMC9368815 DOI: 10.3390/ijms23158608] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Revised: 07/29/2022] [Accepted: 07/30/2022] [Indexed: 12/04/2022] Open
Abstract
Epilepsy is an international public health concern that greatly affects patients’ health and lifestyle. About 30% of patients do not respond to available therapies, making new research models important for further drug discovery. Aquatic vertebrates present a promising avenue for improved seizure drug screening and discovery. Zebrafish (Danio rerio) and African clawed frogs (Xenopus laevis and tropicalis) are increasing in popularity for seizure research due to their cost-effective housing and rearing, similar genome to humans, ease of genetic manipulation, and simplicity of drug dosing. These organisms have demonstrated utility in a variety of seizure-induction models including chemical and genetic methods. Past studies with these methods have produced promising data and generated questions for further applications of these models to promote discovery of drug-resistant seizure pathology and lead to effective treatments for these patients.
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Michiue T, Zorn AM, Kato T, Ochi H, Hayashi T, Inoue T. Versatile Utilities of Amphibians (part 1). Dev Growth Differ 2022; 64:264-265. [PMID: 36088539 DOI: 10.1111/dgd.12805] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/17/2022] [Indexed: 11/30/2022]
Affiliation(s)
- Tatsuo Michiue
- Graduate school of Arts and Sciences, The University of Tokyo, Tokyo, Japan
| | - Aaron M Zorn
- Center for Stem Cell and Organoid Medicine, Division of Developmental Biology, Cincinnati Children's Hospital, Cincinnati, OH, USA
| | - Takashi Kato
- Molecular Physiology, Department of Biology, Faculty of Education and Integrated Arts and Sciences, Waseda University, Tokyo, Japan
| | - Haruki Ochi
- Institute for Promotion of Medical Science Research, Faculty of Medicine, Yamagata University, Yamagata, Japan
| | - Toshinori Hayashi
- Amphibian Research Center, Graduate School of Integrated Sciences for Life, Hiroshima University, Hiroshima, Japan
| | - Takeshi Inoue
- Faculty of Medicine, Tottori University, Yonago, Japan
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